Purpose:
To evaluate long term effect of intravitreal aflibercept in patients with neovascular age-related macular degeneration (nAMD) with persistent intraretinal/subretinal fluid (IRF/SRF) after three monthly consecutive intravitreal ranibizumab injections (IVR).

Methods:
Retrospective, non randomized, comparative clinical study. Patients with nAMD and persistent activity on SD-OCT and treated with at least three consecutive monthly IVR were switched to intravitreal aflibercept injection (IVA) administred according to a pro-re-nata or in a fixed (loading phase+2q8) regimen. At the baseline each patient underwent to a complete ophthalmologic evaluation including best-corrected visual acuity assessment on ETDRS chart, slit lamp examination, fluorescein angiography (FA), indocianin green angiography (ICGA) and SD-OCT. Following the first IVA, each patient in PRN group was monthly examined over a 12-month follow-up period and additional re-treatment was administered if IRF/SRF was confirmed on SD-OCT or new haemorrhages were detected on fundus examination.

Results:
Complete data for 74 patients were collected, 37 in each arm. Mean BCVA showed a substantial stabilization in the PRN group over the entire follow-up (59vs57 letters).<br /> Patients included in the Fixed regimen showed a significant BCVA improvement after the loading phase (59vs62, p:0.0009); however, the improvement was lost at the final visit (59vs61letters). The central retinal thickess (CRT) decreased signficantly from 363±110 to 294±120 (p:0.01) in the PRN group and from 437±165 to 304±92 (p:0.01) in the fixed regimen group.<br /> A complete reabsorption of IRF/SRF was found in 16 of 37 (43%) and in 25 of 37 (65%) in the PRN and in the Fixed Regimen group, respectively, at 12 months. No significant effect was observed in the proportion of eyes showing a pigment epithelium detachment (PED) at the baseline and during the follow-up, although, a significant reduction in the PED height was registered in the Fixed regimen group (228±139 vs 119±119, p:0.01). The mean number of IVA was 3.5 (range: 1-7) in the PRN group and 7 in the Fixed group as per protocol.

Conclusions:
The switch to aflibercept allowed in both regimens a stabilization of morphological and functional parameters. However Fixed regimen determines a greater reduction of CRT, fluid and PED height associated with a slight improvement in the BCVA.